title: Identification of a DNA cytosine methyltransferase gene in conjugative transposon Tn5252.
abstract: The nucleotide sequence of the 3.5-kb right junction fragment of the streptococcal conjugative transposon Tn5252 was obtained. The DNA fragment was found to carry four putative genes one of which displayed a high degree of similarity to prokaryotic 5C-cytosine methyltransferases carrying multiple sequence specificities. No cognate endonuclease gene was detected in the sequenced DNA. Purified methylase polypeptide synthesized in a T7 promoter-controlled overexpression system was found to lack methylase activity while the cell extracts of host cells containing the recombinant plasmid carrying the methylase gene were active. In vivo mutations in the methylase gene did not seem to affect the transferability of the element.
authors.affiliation: Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater 74078, USA.
authors.forename: J
authors.initials: J
authors.lastname: Sampath
authors.forename: M N
authors.initials: MN
authors.lastname: Vijayakumar
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003227:Conjugation, Genetic; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D015870:Gene Expression; D018014:Gene Transfer Techniques; D008969:Molecular Sequence Data; D016296:Mutagenesis; D016366:Open Reading Frames; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013296:Streptococcus pneumoniae / Q000201:enzymology* / Q000235:genetics; D013297:Streptococcus pyogenes / Q000235:genetics
chemical_list: D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D004248:DNA (Cytosine-5-)-Methyltransferases